Dell claims 16ppm for black pages and 4ppm for colour from this machine, indicating that colour images are built up on an intermediate drum, one colour at a time, before being transferred to the paper. In our tests, a five-page black text document took 31 seconds, giving a speed of 9.68ppm, but this increased to 13.33ppm when we printed a longer, 20-page job.
The five-page black text and colour graphics document actually got closer to Dell's quoted speed, with a measured speed of 3.3ppm. A colour photocopy took 41 seconds and a five-page black text photocopy from the ADF completed in just 31 seconds. Both these speeds are impressive for a machine in this market.
We also tried printing photo images and saw times varying from 35 seconds for a 15 x 10cm print from a PC, to 50 seconds for a PictBridge image at 26.5 x 16.5cm. These images were generally good, with smooth graduated tints and reasonable levels of detail in both bright and shadowed areas of images. Colours are a little over-bright, but this serves business graphics quite well.
Black text over coloured backgrounds looks a little blurred, odd for a completely dry ink system, and colour photocopies degrade quite noticeably from the original pages. Black text is sharp and clean - fine for general-purpose documentation.
Although the C1235cn itself is £60 cheaper than the Samsung CLX-3175FW, consumables are more expensive. We couldn't find them discounted at all and have therefore used Dell's prices of just over £47 for each toner cartridge, nearly £114 for the photoconductor drum and £17 for the waste toner container.
This gives a cost per page of 4.7p for an ISO black page and 18.8p for colour, both including 0.7p for paper. These compare with 3.45p and 13.6p, respectively, for pages from the Samsung device, so you would make up the £60 difference between the two machines after you've printed 4,800 black pages, or just 1,150 colour ones. These page costs are not particularly good, even for an inexpensive colour laser.
So which of the two machines should you go for? If you want to connect wirelessly, there's no real issue, as this Dell machine only has cabled networking. It's also more expensive to run than its Samsung counterpart, largely because Samsung sells its consumables through a wide chain of third-parties, who are prepared to discount. In other respects the two machines are very similar, so based on TCO we have to go for the Samsung.